The quality of the colored substrate, an important component of a liquid crystal display, directly affects the quality of the liquid crystal display. A colored substrate generally comprises a colored layer formed from three colored photoresists (red, green, and blue). In a colored substrate, there are some requirements on the slope angle of the edge of the colored film layer. If the slope angle is too large, it may cause the missing of an orientation layer during the subsequent orientation layer coating process, thereby making it prone to light leakage.
Currently, the colored layer is often formed by exposure and development on a colored photoresist. A colored photoresist primarily comprises a polymerizable monomer, an alkaline soluble resin, a pigment dispersion, a photoinitiator, a solvent, and the like. After exposure and high temperature post-baking, the polymerizable monomer will polymerize to form a polymer. However, based on empirical data obtained by comparing the high temperature post-baking of various monomers, polymers formed from common polymerizable monomers have too high hardness which causes high brittleness of the edge of the film layer and poor fluidity under gravity, making it not prone to bending and depressing, which results in a smooth slope with a high slope angle, usually higher than 75°, making it prone to light leakage.